Celery Breaking `pymongo[srv]` with `pymongo==4.8.0` (Fix)

The Fix

pip install celery==5.5.0

Based on closed celery/celery issue #9254 · PR/commit linked

Production note: This usually shows up under retries/timeouts. Treat it as a side-effect risk until you can verify behavior with a canary + real traffic.

Jump to Verify Open PR/Commit

@@ -1 +1 @@
@@ -1 +1 @@
-pymongo[srv]>=4.0.2, <4.9
+pymongo>=4.3, <4.9

repro.py

Traceback (most recent call last):
  File "/home/francis/dev/conda/envs/weaver/lib/python3.10/site-packages/pkg_resources/__init__.py", line 3097, in requires
    deps.extend(dm[safe_extra(ext)])
KeyError: 'srv'

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/home/francis/dev/conda/envs/weaver/bin/weaver", line 33, in <module>
    sys.exit(load_entry_point('weaver', 'console_scripts', 'weaver')())
  File "/home/francis/dev/conda/envs/weaver/bin/weaver", line 25, in importlib_load_entry_point
    return next(matches).load()
  File "/home/francis/dev/conda/envs/weaver/lib/python3.10/importlib/metadata/__init__.py", line 171, in load
    module = import_module(match.group('module'))
  File "/home/francis/dev/conda/envs/weaver/lib/python3.10/importlib/__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1050, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1027, in _find_and_load
  File "<frozen importlib._bootstrap>", line 1006, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 688, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 883, in exec_module
  File "<frozen importlib._bootstrap>", line 241, in _call_with_frames_removed
  File "/home/francis/dev/weaver/weaver/cli.py", line 17, in <module>
    from pyramid.httpexceptions import HTTPNotImplemented
  File "/home/francis/dev/conda/envs/weaver/lib/python3.10/site-packages/pyramid/httpexceptions.py", line 139, in <module>
    from pyramid.util import text_
  File "/home/francis/dev/conda/envs/weaver/lib/python3.10/site-packages/pyramid/util.py", line 8, in <module>
    from pyramid.path import DottedNameResolver as _DottedNameResolver
  File "/home/francis/dev/conda/envs/weaver/lib/python3.10/site-packages/pyramid/path.py", line 3, in <module>
    import pkg_resources
  File "/home/francis/dev/conda/envs/weaver/lib/python3.10/site-packages/pkg_resources/__init__.py", line 3657, in <module>
    def _initialize_master_working_set():
  File "/home/francis/dev/conda/envs/weaver/lib/python3.10/site-packages/pkg_resources/__init__.py", line 3640, in _call_aside
    f(*args, **kwargs)
  File "/home/francis/dev/conda/envs/weaver/lib/python3.10/site-packages/pkg_resources/__init__.py", line 3669, in _initialize_master_working_set
    working_set = _declare_state('object', 'working_set', WorkingSet._build_master())
  File "/home/francis/dev/conda/envs/weaver/lib/python3.10/site-packages/pkg_resources/__init__.py", line 656, in _build_master
    ws.require(__requires__)
  File "/home/francis/dev/conda/envs/weaver/lib/python3.10/site-packages/pkg_resources/__init__.py", line 1063, in require
    needed = self.resolve(parse_requirements(requirements))
  File "/home/francis/dev/conda/envs/weaver/lib/python3.10/site-packages/pkg_resources/__init__.py", line 895, in resolve
    new_requirements = dist.requires(req.extras)[::-1]
  File "/home/francis/dev/conda/envs/weaver/lib/python3.10/site-packages/pkg_resources/__init__.py", line 3099, in requires
    raise UnknownExtra(
pkg_resources.UnknownExtra: pymongo 4.8.0 has no such extra feature 'srv'

verify

Re-run the minimal reproduction on your broken version, then apply the fix and re-run.

fix.md

Option A — Upgrade to fixed release\npip install celery==5.5.0\nWhen NOT to use: Do not apply this fix if you rely on the `[srv]` extra for your MongoDB connections.\n\nOption C — Workaround\nPR fix: https://github.com/crim-ca/weaver/pull/709\nWhen NOT to use: Do not apply this fix if you rely on the `[srv]` extra for your MongoDB connections.\n\n

Why This Fix Works in Production

Trigger: deps.extend(dm[safe_extra(ext)])
Mechanism: Updated the MongoDB requirements to remove the deprecated `[srv]` extra requirement, fixing the issue with `pymongo==4.8.0`.
Why the fix works: Updated the MongoDB requirements to remove the deprecated `[srv]` extra requirement, fixing the issue with `pymongo==4.8.0`. (first fixed release: 5.5.0).

Production impact:

If left unfixed, the same config can fail only in production (env differences), causing startup failures or partial feature outages.

Why This Breaks in Prod

Shows up under Python 3.10 in real deployments (not just unit tests).
Surfaces as: Traceback (most recent call last):

Proof / Evidence

GitHub issue: #9254
Fix PR: https://github.com/celery/celery/pull/9258
First fixed release: 5.5.0
Reproduced locally: No (not executed)
Last verified: 2026-02-09
Confidence: 0.85
Did this fix it?: Yes (upstream fix exists)
Own content ratio: 0.27

Discussion

High-signal excerpts from the issue thread (symptoms, repros, edge-cases).

Jump to Sources Open on GitHub

“@thedrow PR opened: https://github.com/celery/celery/pull/9258”

@fmigneault · 2024-09-11 · source

Failure Signature (Search String)

deps.extend(dm[safe_extra(ext)])

Error Message

Stack trace

error.txt

Error Message
-------------
Traceback (most recent call last):
  File "/home/francis/dev/conda/envs/weaver/lib/python3.10/site-packages/pkg_resources/__init__.py", line 3097, in requires
    deps.extend(dm[safe_extra(ext)])
KeyError: 'srv'

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/home/francis/dev/conda/envs/weaver/bin/weaver", line 33, in <module>
    sys.exit(load_entry_point('weaver', 'console_scripts', 'weaver')())
  File "/home/francis/dev/conda/envs/weaver/bin/weaver", line 25, in importlib_load_entry_point
    return next(matches).load()
  File "/home/francis/dev/conda/envs/weaver/lib/python3.10/importlib/metadata/__init__.py", line 171, in load
    module = import_module(match.group('module'))
  File "/home/francis/dev/conda/envs/weaver/lib/python3.10/importlib/__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1050, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1027, in _find_and_load
  File "<frozen importlib._bootstrap>", line 1006, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 688, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 883, in exec_module
  File "<frozen importlib._bootstrap>", line 241, in _call_with_frames_removed
  File "/home/francis/dev/weaver/wea
... (truncated) ...

Minimal Reproduction

repro.py

Traceback (most recent call last):
  File "/home/francis/dev/conda/envs/weaver/lib/python3.10/site-packages/pkg_resources/__init__.py", line 3097, in requires
    deps.extend(dm[safe_extra(ext)])
KeyError: 'srv'

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/home/francis/dev/conda/envs/weaver/bin/weaver", line 33, in <module>
    sys.exit(load_entry_point('weaver', 'console_scripts', 'weaver')())
  File "/home/francis/dev/conda/envs/weaver/bin/weaver", line 25, in importlib_load_entry_point
    return next(matches).load()
  File "/home/francis/dev/conda/envs/weaver/lib/python3.10/importlib/metadata/__init__.py", line 171, in load
    module = import_module(match.group('module'))
  File "/home/francis/dev/conda/envs/weaver/lib/python3.10/importlib/__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1050, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1027, in _find_and_load
  File "<frozen importlib._bootstrap>", line 1006, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 688, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 883, in exec_module
  File "<frozen importlib._bootstrap>", line 241, in _call_with_frames_removed
  File "/home/francis/dev/weaver/weaver/cli.py", line 17, in <module>
    from pyramid.httpexceptions import HTTPNotImplemented
  File "/home/francis/dev/conda/envs/weaver/lib/python3.10/site-packages/pyramid/httpexceptions.py", line 139, in <module>
    from pyramid.util import text_
  File "/home/francis/dev/conda/envs/weaver/lib/python3.10/site-packages/pyramid/util.py", line 8, in <module>
    from pyramid.path import DottedNameResolver as _DottedNameResolver
  File "/home/francis/dev/conda/envs/weaver/lib/python3.10/site-packages/pyramid/path.py", line 3, in <module>
    import pkg_resources
  File "/home/francis/dev/conda/envs/weaver/lib/python3.10/site-packages/pkg_resources/__init__.py", line 3657, in <module>
    def _initialize_master_working_set():
  File "/home/francis/dev/conda/envs/weaver/lib/python3.10/site-packages/pkg_resources/__init__.py", line 3640, in _call_aside
    f(*args, **kwargs)
  File "/home/francis/dev/conda/envs/weaver/lib/python3.10/site-packages/pkg_resources/__init__.py", line 3669, in _initialize_master_working_set
    working_set = _declare_state('object', 'working_set', WorkingSet._build_master())
  File "/home/francis/dev/conda/envs/weaver/lib/python3.10/site-packages/pkg_resources/__init__.py", line 656, in _build_master
    ws.require(__requires__)
  File "/home/francis/dev/conda/envs/weaver/lib/python3.10/site-packages/pkg_resources/__init__.py", line 1063, in require
    needed = self.resolve(parse_requirements(requirements))
  File "/home/francis/dev/conda/envs/weaver/lib/python3.10/site-packages/pkg_resources/__init__.py", line 895, in resolve
    new_requirements = dist.requires(req.extras)[::-1]
  File "/home/francis/dev/conda/envs/weaver/lib/python3.10/site-packages/pkg_resources/__init__.py", line 3099, in requires
    raise UnknownExtra(
pkg_resources.UnknownExtra: pymongo 4.8.0 has no such extra feature 'srv'

Environment

Python: 3.10

Fix Options (Details)

Option A — Upgrade to fixed release Safe default (recommended)

pip install celery==5.5.0

When NOT to use: Do not apply this fix if you rely on the `[srv]` extra for your MongoDB connections.

Use when you can deploy the upstream fix. It is usually lower-risk than long-lived workarounds.

Option C — Workaround Temporary workaround

PR fix: https://github.com/crim-ca/weaver/pull/709

When NOT to use: Do not apply this fix if you rely on the `[srv]` extra for your MongoDB connections.

Use only if you cannot change versions today. Treat this as a stopgap and remove once upgraded.

Option D — Guard side-effects with OnceOnly Guardrail for side-effects

Mitigate duplicate external side-effects under retries/timeouts/agent loops by gating the operation before calling external systems.

Place OnceOnly between your code/agent and real side-effects (Stripe, emails, CRM, APIs).
Use a stable key per side-effect (e.g., customer_id + action + idempotency_key).
Fail-safe: configure fail-open vs fail-closed based on blast radius and spend risk.

Show example snippet (optional)

onceonly.py

from onceonly import OnceOnly
import os

once = OnceOnly(api_key=os.environ["ONCEONLY_API_KEY"], fail_open=True)

# Stable idempotency key per real side-effect.
# Use a request id / job id / webhook delivery id / Stripe event id, etc.
event_id = "evt_..."  # replace
key = f"stripe:webhook:{event_id}"

res = once.check_lock(key=key, ttl=3600)
if res.duplicate:
    return {"status": "already_processed"}

# Safe to execute the side-effect exactly once.
handle_event(event_id)

See OnceOnly SDK

When NOT to use: Do not use this to hide logic bugs or data corruption. Use it to block duplicate external side-effects and enforce tool permissions/spend caps.

Fix reference: https://github.com/celery/celery/pull/9258

First fixed release: 5.5.0

Last verified: 2026-02-09. Validate in your environment.

When NOT to Use This Fix

Do not apply this fix if you rely on the `[srv]` extra for your MongoDB connections.
Do not use this to hide logic bugs or data corruption. Use it to block duplicate external side-effects and enforce tool permissions/spend caps.

Verify Fix

verify

Re-run the minimal reproduction on your broken version, then apply the fix and re-run.

Did This Fix Work in Your Case?

Quick signal helps us prioritize which fixes to verify and improve.

Prevention

Capture the exact failing error string in logs and tests so you can reproduce via a minimal script.
Pin production dependencies and upgrade only with a reproducible test that hits the failing path.

Version Compatibility Table

Version	Status
5.5.0	Fixed

Related Issues

No related fixes found.

Cluster: celery:configuration-error Celery hub Celery best practices All hubs All clusters

Related clusters: Data consistency Duplicates Duplicate processing

Sources

We don’t republish the full GitHub discussion text. Use the links above for context.